Evidence for early life comes from fossils. (a) (i) What is a fossil?



Download 128.3 Kb.
Date conversion20.05.2016
Size128.3 Kb.



Q1.Evidence for early life comes from fossils.

(a)     (i)      What is a fossil?

...............................................................................................................

...............................................................................................................

...............................................................................................................

...............................................................................................................

...............................................................................................................

(2)




(ii)     We do not have a complete fossil record from the beginning of life on Earth.

Suggest two reasons why.

...............................................................................................................

...............................................................................................................

...............................................................................................................

...............................................................................................................

...............................................................................................................



(2)




(b)     The sea erodes cliffs at the coast. Some cliffs have layers of rocks.

The diagram shows a cliff at the coast.

The cliff has four layers of rock, A, B, C and D, that contain fossils.

 
                                                           © Adrian Bicker / Science Photo Library

Which layer of rock, A, B, C or D, is likely to contain the oldest fossils?

Write your answer in the box.         

Explain your answer.

........................................................................................................................

........................................................................................................................



(2)




(c)     The fossil record shows that some animals have become extinct.

Give three possible reasons why animals become extinct.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

(3)

(Total 9 marks)


Q2.The photograph shows a fossil footprint. The fossil was found in a rock at the bottom of a shallow river.

Scientists believe this is the footprint of a dinosaur. The dinosaur was alive 110 million years ago.

 

© Pearl Jackson/iStock

(a)     (i)      Suggest how the fossil shown in the photograph was formed.

...............................................................................................................

...............................................................................................................

(1)
(ii)     Fossils may also be formed by other methods.

Describe one other method of forming a fossil.

...............................................................................................................

...............................................................................................................



(1)

(b)     Dinosaurs are now extinct.

Give two factors that can cause extinction.

1 .....................................................................................................................

........................................................................................................................

2 .....................................................................................................................

........................................................................................................................

(2)
(c)     How can fossils give evidence for evolution?

........................................................................................................................

........................................................................................................................

(1)

(d)     Scientists are uncertain about how life began on Earth.

Why?

........................................................................................................................



........................................................................................................................

(1)

(Total 6 marks)





Q3.    In the Grand Canyon, scientists have found fossils of several different groups of organisms.
The diagram shows the number and age of the fossils that the scientists found.
The width of each shaded area shows the number of fossils found.

(a)     What is a fossil?

........................................................................................................................

........................................................................................................................

........................................................................................................................

(2)



(b)

(i)

Which group of organisms, ABC or D, was the first to evolve?

http://content.doublestruck.eu/getpicture.asp?sub=ag_bl&ct=q&org=b4781620c73aa97ce4807769cbe84de2&folder=q12s2f03_files&file=8_img02.png

(1)

(ii)

Which group of organisms, ABC or D, is now extinct?

http://content.doublestruck.eu/getpicture.asp?sub=ag_bl&ct=q&org=b4781620c73aa97ce4807769cbe84de2&folder=q12s2f03_files&file=8_img02.png

(1)

(iii)    Give one environmental factor that might have caused this group of organisms to become extinct.

........................................................................................................................

........................................................................................................................



(1)




(c)     Scientists suggested that, 10 million years ago, organisms of Group C were more common than organisms from any of the other groups.

What is the evidence for this in the diagram?

........................................................................................................................

........................................................................................................................

(1)



(d)     The scientists suggested that the four groups of fossilised organisms evolved from a common ancestor.

Which of the following would provide the best evidence that their suggestion is correct?

Tick (images) one box.

 


Statement

Tick (images)

All the groups lived in the same area.

 

Fossils from each group were found in the same rock layer.

 

Members of the groups have similar physical structures.

 


(1)

(Total 7 marks)

Q4.          Choose words from this list to complete the sentences below.

bones                         extinct                   fossils

muscles                      rocks

          In the past some types of animals and plants have died out.

          They have become ........................................ .

          We know about these animals and plants because we find them as ........................................ .

          Sometimes the hard parts of animals such as ........................................ did not decay.

          In other cases the bodies of animals and plants were replaced by minerals.

          You can still see their shape in ........................................ .

(Total 4 marks)

 


Q5.          During evolution, many groups of animals have become extinct (died out).

(a)     The graph shows how the number of animal groups has changed over time.



Harold L Levin, The Earth Through Time,© 2005,


Reprinted with permission of John Wiley & Sons, Inc.

How has the number of animal groups changed between 200 million years ago and the present day?

........................................................................................................................

........................................................................................................................



(1)
(b)     In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.

Describe the different causes of the extinction of organisms.


Your description should include possible reasons for the mass extinctions shown on the graph.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

(6)

(Total 7 marks)

 
Q6.          There is a large amount of evidence that evolution is taking place.

(a)     Scientists are uncertain about how life started on Earth.

Explain why.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................



(2)

(b)     Salamanders are terrestrial amphibians.

The diagram shows the distribution of four different species of salamander in a country.

Originally, there was only one species of salamander in the country.

Suggest an explanation for the development of the four different species.

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

........................................................................................................................

(5)

(Total 7 marks)

 
Q7.          The drawing shows some of the fossils found in the layers of rock in two cliffs.

          The two cliffs are on opposite sides of a large valley.

          Geologists think that the valley has been carved out by rivers, and that the order of rock layers has not changed.




(a)     (i)      Which of the rock layers, A, B, C or D, is the oldest? ...................................



(1)

(ii)     Give the letters of two layers of rock on opposite sides of the valley that are the same age.

.............................. and ..............................

(1)




(b)     How do fossils provide evidence for the theory of evolution?

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................



(2)

(Total 4 marks)

 

 




Q8.          Fossils give us evidence for the theory of evolution.

          The diagrams show how a fish became a fossil.

(a)     In the sentences below, cross out the two lines which are wrong in each box.



(4)




(b)     Give one way in which fossils provide evidence for the theory of evolution.

....................................................................................................................................

....................................................................................................................................



(1)

(Total 5 marks)
 

M1.(a)     (i)      ‘remains’ of organisms

allow examples eg bones / shells / rootlet traces / burrows / tracks

1




any one from:

•        from many years ago

allow eg ‘hundreds of years’

•        in rocks



1




(ii)     any two ideas from:

•        not yet found

•        were never formed

•        destroyed (by geological activity)

2




(b)     D



1




idea of deeper rocks being formed earlier



do not allow just ‘deeper / lower’

1




(c)     any three from:

•        changes to the environment over long periods of / geological time

do not allow just ‘changes to the environment’ an idea of long time scale is required

•        new predators



do not allow predators, alone

•        new diseases



do not allow disease, alone

•        new (more successful) competitors



do not allow competitors, alone

•        catastrophic event / example

•        cyclical nature of speciation

3

[9]










M2.(a)     (i)      animal walking on soft material or suitably named material

or

further detail – eg dries out / buried / hardens / turns to rock



do not allow general descriptions of how fossils are formed or reference to bones not decaying

1




(ii)     any one from:

•        (from) bones / shells / hard parts or from parts that do not decay / rot or are preserved

ignore imprint / impression

•        animal trapped in resin / amber / ice / peat



allow frozen

•        infiltration with minerals / named



1




(b)     any two from:

examples of physical factors such as flooding, volcanic activity (allow volcanoes) asteroid collision, drought, ice age / temperature change

accept 2 physical factors or 2 biological factors or one of each for full marks

ignore pollution

examples of biological factors such as predators (allow hunters), disease / named pathogen, competition lack of food / mates, cyclical nature of speciation / isolation / lack of habitat or habitat change



If no other answers given allow natural disaster / climate change / weather change / catastrophic event / environmental change for 1 mark

2




(c)     older fossils simpler



to gain the mark there must be implication of change

or

change (with time)

ignore evolve
ignore extinction


1




(d)     insufficient / no evidence / no remains or fossils survive



ignore no people were there

allow no proof

1

[6]










M3.          (a)     remains of an organism or bone / shell / hard part of an organism / impression

1

further detail – eg in rock / from a long time ago



if numbers, greater or equal to hundreds of years
allow made of minerals
ignore over time
ignore fossil are rocks


1




(b)     (i)      D



1

(ii)     B



1




(iii)     predation / disease / lack of food / competition / loss of habitat /


 climate change / catastrophic event – or volcanic eruption / flood /
 drought / temperature change / weather change / ice age / change in atmosphere

ignore human effects
ignore pollution effects / acid rain


allow natural disaster

1




(c)     C = ‘widest’ thickest / widerthicker column or more fossils


(of type C found)

         allow biggest / er



1




(d)     members of the groups have similar physical structures



extra box ticked – cancel

1

[7]

 


M4.          extinct (NOT fossils)
fossils
bones
rocks

each for 1 mark

[4]

 

 




M5.          (a)     increased by about 7 times / from 600 to 4300 / by 3700

1




(b)     Marks awarded for this answer will be determined by the Quality


of Written Communication (QWC) as well as the standard of the
scientific response.

No relevant content



0 marks

There is a brief description of at least two causes of


extinction, which has little clarity and detail.

Level 1 (1–2 marks)

There is a description of some causes of extinction,


including both small-scale and large-scale events but
there is a lack of clarity and detail.

Level 2 (3–4 marks)

There is a clear, balanced and detailed description of at


least five causes of extinction, including both small-scale
and large-scale events.

Level 3 (5–6 marks)






examples of biology points made in the response:

•        changes to the environment / named changes

•        new competitors

•        new diseases

•        new predators

•        volcanic eruptions

•        collisions with asteroids

[7]

 

 




M6.          (a)     there is a lack of valid / reliable evidence

1

because the early organisms were soft bodied or because remains were


destroyed by geological action

1




(b)     populations of salamanders became isolated / separated



1

by areas between mountains



1

there was genetic variation in these isolated communities



1

natural selection acted differently on these isolated communities



1

eventually resulting in interbreeding being no longer possible and so


new species have been formed

1

[7]

 

 




M7.          (a)     (i)      D

for 1 mark

1

(ii)     D    Y (both) or C   X (both) or B   W (both)



for 1 mark

1




(b)     N.B. answers must relate to fossils providing evidence


show types of animals / plants that no longer exist / named ref eg dinosaur
show changes in types (of animals / plants)
similar fossils found in rocks of similar age
reference to sequence of change
or example
e.g. horse / limb

any two for 1 mark each

2

[4]

 

 




M8.          (a)     mud

1

decayed


1

skeleton


1

rock


1




(b)     idea that living things have changed (over time)



do not allow ‘dating’
do
not credit ‘evolved’
allow ‘compare the skeleton’


1

[5]

 

 


 

E2.(a)     (i)      Less than one third of the students could give an adequate explanation of how the fossil of the dinosaur footprint might have been formed. Answers were very mixed, but most students who gained a mark did so by describing the way in which the footprint was made by treading in soft mud. Many wrote that the fossil was formed from dinosaur bones, even though the question told them that it was a footprint.

(ii)     Many students gained a mark for reference to bones, shells or whole animals trapped in ice or amber. Just over one third of students were able to give an adequate description of a method of fossil formation.

(b)     Nearly all students knew at least one possible cause of extinction, with approximately half being able to give two causes, ranging from physical factors such as flooding, volcanic activity, asteroid collision, drought, or an ice age, to biotic factors such as predation, disease or competition for food.

(c)     Less than one third of students were able to explain how changes in fossils with time might give evidence for evolution. Very few made the point that older fossils were simpler. Failure to score was often because of the use of the word ‘evolve’ to mean change: ‘ evolution ’ was given in the question and so ‘evolve’ could not gain credit. There were vague references to adaptation to the environment, which often referred to just a single organism rather than to organisms changing over time.

(d)     Many answers here were vague or confused. There was confusion between the origin of life and the origin of the universe. Some answers referred to conflicting theories about how life began on earth or stated that there were no people there to record events! A little over half the students were able to explain that there was insufficient evidence, such as a lack of suitable fossils.




E3.          (a)     As the diagram indicated, a fossil is likely to have been formed from an organism that was alive millions of years ago (rather than just “many years”). Details, such as being an impression (e.g. a footprint) or being formed in rock, were also acceptable as part of the answer. Most students were able to make at least one correct point, but less than half could give two.

(b)     What should have been obvious from the diagram proved to be so for only three-quarters of the students who correctly selected group D as the group of organisms which were first to evolve.   Slightly more realised that the diagram gave evidence that group B was now extinct.   Most students were also able to suggest an environmental factor that might have caused extinction, such as predation, lack of food, competition or some catastrophic event.


(c)     Around three-quarters of students successfully described that group C’s fossils were the most common 10 million years ago (or that this group had the widest band in the diagram for that time).   Some students merely re-stated the words of the question and so gained no credit.

(d)     Around two-thirds correctly selected the fact that having similar physical structures would indicate that all four groups of organisms had evolved from a common ancestor.

 

E4.          Very well answered by most candidates with a small minority reversing “extinct” and “fossils”.

 

 


E8.          This proved to be a good opening question for most candidates. It produced generally high scores.

(a)     The majority of candidates were able to score full marks. In a few cases however, the candidates had not followed the instructions in the rubric concerning the method of indicating their answers. In general, the candidates’ intentions were clear but in a few cases there were so many crossings out, ringing and re-writing that it was difficult for examiners to decide what the candidate had intended.

(b)     This proved to be more demanding, with only a minority of the candidates realising that evidence came from a comparison between fossils and present day specimens. Most of the other candidates either talked about the dating of fossils or left the question unanswered.

 

 


 

Resource currently unavailable.





The database is protected by copyright ©essaydocs.org 2016
send message

    Main page